Role of nano-zirconia in the mechanical properties improvement of resin cement used for tooth fragment reattachment

Dental fractures of the anterior teeth are a common form of dental trauma. Reattachment of fractured tooth fragment by means of self-adhesive resin cement is currently compromised by the poor mechanical properties of these ceramics. Herein, we synthesized zirconium dioxide nanoparticles (nano-ZrO2) using the Co-precipitation approach and then mixing it in different concentrations (1.0, 2.0, 3.0, and 5.0 wt%) with the commercially available RelyX (TM) Unicem self-adhesive universal resin cement (ARC) forming, nano-ZrO2/ARC. Both the synthesized nano-ZrO2 and nano-ZrO2/ARC were characterized using a high-resolution transmission electron microscope (HR-TEM), field-emission scanning electron microscope, X-ray diffraction, and Fourier transform infrared technique. The HR-TEM images revealed that the synthesized nano-ZrO2 was spherical with a size of similar to 12 nm. The results showed that the addition of nano-ZrO2 significantly enhanced the mechanical properties as fracture resistance, compressive strength, diametral tensile, and micro-hardness values of the resin cement. The mixing 3.0 wt% of nano-ZrO2 with ARC revealed the maximum improvement in the mechanical properties and, consequently, the resin's repair strength. Their incorporation with ARC up to 3.0% wt did not cause significant cell death than ARC alone. We believe that the information discussed here might be relevant to the stability of nano-ZrO2-modified resin cement and, therefore, to its clinical usage for fragment tooth reattachment, cementation of dental crowns, bridges, and bands.

Automated summary

Zirconium dioxide nanoparticles were synthesized and mixed with a resin cement, significantly enhancing the mechanical properties. The optimal improvement in mechanical properties was achieved by adding 3.0 wt% nano-ZrO2. Incorporation of nano-ZrO2 up to 3.0% wt did not cause significant cell death, indicating potential clinical usage for dental applications.